Most Macs running 10.7, 10.8, 10.9 and 10.10 can be updated to 10.11.
Some older computers like the MacPro1,1 and 2,1 do not support a newer macOS.
For these systems we would suggest a Mac mini and move your ATTO SAS or FC card inside a Sonnet Thunderbolt enclosure.

A good way to upgrade is to use a new drive or a second partition on an
existing drive.
If you have a fixed drive inside your Mac then ensure you use a program
like SuperDuper to backup the entire boot drive to an external drive. Then
reformat the internal drive.
This gives you a clean install, but doesn't destroy the data on your old
system. So if needed you can boot the old macOS or copy across items that
are missing.
Even if you don't want to update to a new major version, we would recommend that you run the latest minor version. For example if
you are on 10.11.2 update to 10.11.6.

Please get in touch with support@yoyotta.com if you need any help or have further questions.

macOS 10.13 and newer System Security

New installs of drivers and system software from ATTO, OSXFUSE (developer is Benjamin Fleischer) may need approval. You will see a message saying System Extension BlockedAlso the first time you use YoYotta to read TAR tapes on a new High Sierra system, you will need to approve YoYotta System Software.
Open the Security & Privacy page in Apple System Preferences, unlock the padlock and click Allow to enable the System software to load.
You must click the Allow button directly on the Mac, clicking using remote screen sharing will not work.
If the Allow button is not shown then reboot your Mac and check the Security & Privacy page again.